Yes, you will be able to run them all at 1600Mhz, and no you don't need to buy both 1600 and 1333. The diagram you are referring to is letting you know that 1333 and 1600 DIMMs are available. The available slotting to the right of that does not mean you need 1600 in the A lane and 1333 in the B lane. It is an either or. An easier way to read it would be something like this:

8GB available in 1333 OR 1600 - Slot population 1-4

There are two factors that will downclock 1600MHz memory to 1333. If you mix anything other than 1600MHz memory it will drop the frequency of all DIMMs to the lowest common frequency. Also, if you populate more than 2 DIMMs per channel it will max the frequency to 1066/800, so you can't use slots 9-12 if you want to have 1333 or 1600MHz frequencies.

So in short, if you buy 8x8GB 1600 MHz DIMMs and populate them in slots 1-4 in both the A and B lanes then they will operate at 1600MHz.

Some of the other configurations, depending on the max capacity, module size and number of modules, indicate you would run all 1333 or all 1600, I am just confused why it would require two speeds for the different CPUs with 64GB.

Do you know what configuration you are running- max capacity, module size and number of modules?

Some of the other configurations, depending on the max capacity, module size and number of modules, indicate you would run all 1333 or all 1600, I am just confused why it would require two speeds for the different CPUs with 64GB.

Do you know what configuration you are running- max capacity, module size and number of modules?

Thanks.

I bought my modules directly from Dell. They are the 8GB RDIMM 1600Mhz modules and those are the only modules I have in the server. You don't want to use the lower speed sticks because then all the RAM will run at that lower speed.

So I would buy 8 of the 8GB RDIMM 1600Mhz modules and then put one stick in each channel as there are 4 channels per processor.

Yes, you will be able to run them all at 1600Mhz, and no you don't need to buy both 1600 and 1333. The diagram you are referring to is letting you know that 1333 and 1600 DIMMs are available. The available slotting to the right of that does not mean you need 1600 in the A lane and 1333 in the B lane. It is an either or. An easier way to read it would be something like this:

8GB available in 1333 OR 1600 - Slot population 1-4

There are two factors that will downclock 1600MHz memory to 1333. If you mix anything other than 1600MHz memory it will drop the frequency of all DIMMs to the lowest common frequency. Also, if you populate more than 2 DIMMs per channel it will max the frequency to 1066/800, so you can't use slots 9-12 if you want to have 1333 or 1600MHz frequencies.

So in short, if you buy 8x8GB 1600 MHz DIMMs and populate them in slots 1-4 in both the A and B lanes then they will operate at 1600MHz.